The present invention relates to an optometric device, in particular eyeglasses including semi-rimless frames having a lens retention system for mounting lenses having a circumferential groove therearound.
Mounting systems for circumferentially grooved lenses are known in the art, but in the past have had numerous problems associated therewith which made the commercial utilization thereof undesirable although the use of this type of lens is desirable since the grinding of the lens is simplified and it provides stability and rigidness when properly mounted.
The prior art systems were directed exclusively to metal frames wherein a plastic rib which is a separately molded piece is mechanically attached to the frame. This system has the disadvantages of being extremely costly and unreliable since the molded piece often separates from the frame.
Moreover, lens retention systems are known which utilize a line and winder device for maintaining the lens in position, however the winding device is made of plastic and is unthreaded but which is not self-locking and is therefore capable of undesired loosening or opening.